This invention relates generally to X-ray imaging, including diagnostic radiography and computed tomography (CT). Specifically, the invention relates to the use of X-ray anti-scatter grids to improve image quality.
In X-ray imaging, primary radiation photons are emitted from an X-ray source towards an X-ray detector. They pass through an object to be imaged. Some of the photons are scattered within the object and are re-directed towards another path. These scattered photons arrive at the detector at random directions and add an overlying haze to the image, reducing image quality or creating artifacts.
Anti-scatter grids are often employed to reduce the detection of scattered radiation. Anti-scatter grids comprise lamellae, or plates of X-ray attenuating material, that are parallel to the ray path between source and detector. The placement of these lamellae causes them to selectively block scattered radiation over primary radiation. However, residual scatter remains even with an anti-scatter grid. The residual scatter can still cause artifacts.
It would therefore be valuable to have a mechanism for estimating the scatter that remains even after the anti-scatter grid.